Madou Coulibaly created TEIID-4880: -------------------------------------- Summary: Join Elimination in Star Schema Key: TEIID-4880 URL: https://issues.jboss.org/browse/TEIID-4880 Project: Teiid Issue Type: Feature Request Components: Query Engine Affects Versions: 8.7.11.6_2 Reporter: Madou Coulibaly Assignee: Steven Hawkins Suppose we have the following star schema : * Fact_Sales (Fact table) * Dim_Date, Dim_Store and Dim_Product (Dimension tables) Each table has a PK (id field) Fact_Sales has a foreign key for each dimension (date_id, store_id, product_id) in order to link them. Then, suppose we create an aggregate view of the fact table and its dimensions: _SELECT * FROM Fact_Sales F INNER JOIN Dim_Date D ON (F.Date_Id = D.Id) INNER JOIN Dim_Store S ON (F.Store_Id = S.Id) INNER JOIN Dim_Product P ON (F.Product_Id = P.Id)_ Suppose now we only project fields from the fact table (Fact_Sales) and just one of its dimension (Dim_Product) in a query: _SELECT Fact_Sales.*, Dim_Product.* FROM aggregate_view_ During the Query Optimization, Teiid should be able to use the PK_FK constraints which link the fact table with its dimension in order to deduct that no fields from the other dimensions (Dim_Date, Dim_Store) are projected so the joins with these tables can be removed for the Query Plan. -- This message was sent by Atlassian JIRA (v7.2.3#72005)